The invention generally relates to stabilizing a flow along a wellbore.
For purposes of producing well fluid from a particular wellbore, a string may be run into the wellbore; and isolation zones, or segments, may be created by setting packers of the string. In this regard, when set, each packer forms a corresponding annular seal between the string and the wellbore wall or casing string (if the wellbore is cased). The string may receive incoming well fluid in each of the isolated segments.
Without compensation, the incoming flow distribution along the string may be non-uniform, as the pressure drop across the string inherently changes along the string's length. Furthermore, the flow non-uniformity may also be attributable to variations in reservoir conditions along the wellbore.
A generally uniform, or stabilized, flow into the string permits a maximum reservoir sweep and improves the overall oil production. Furthermore, an uneven flow introduces the possibility of crossflow, which may damage the reservoir. A uniform flow is also beneficial when the flow is an injection flow, which is directed out of the string and into the well.
Conventionally, the string may include flow control devices called chokes for purposes of attempting to stabilize the incoming flow. As an example, in each isolated segment, the string may contain a choke that has an adjustable cross-sectional flow path for purposes of controlling communication between the string and the well. The settings of the chokes (i.e., the cross-sectional flow areas) along the string may be varied in an attempt to achieve a uniform flow distribution. The chokes may be pre-set before the string is run into the well. After the string is in place in the well, the choke settings may be changed, for example, by engaging the chokes with a tool (a shifting tool, for example) during an intervention.